1. Field of the Invention
The invention is a miniature, light weight, high voltage, high frequency, high power output ballast, particularly adapted for use with cold cathode lights, and herein concealable within and useful with a unique sealed neon lamp structure.
2. Description of the Prior Art
U.S. Pat. No. 4,700,111, issued Oct. 13, 1987 to Folwell et al, and entitled HIGH FREQUENCY BALLAST CIRCUIT is typical of high frequency switching circuits of the prior art.
The design of this prior art circuit is based upon the use of a U--U core. Applicants have substantially improved efficiency, and output power to size, including tighter coupling by using an E--E core with entirely different winding structures. Also, applicants have extended the range of their miniature ballast for nominally handling 2' to 26' and even 30', 12 mm diameter, neon lamps, rather than the 10' lamps of the described prior art. U.S. Ser. No. 06/891,263 now U.S. Pat. No. 4,751,434 by Helling et al discloses sealed displays including cold cathode tubes.